We have BBSA 8.0 setup on windows enviornment, Whenever I execute any job through BBSA console My server CPU utilization goes to 100%, irrespective of Job volume. Even if i try to update any property through a Job it will reach 100%, does any one came accross such issue? what could be the possible reasons?

what is the minor version? SP level, I mean? Is the application server version ( Minor included) same as the console version? Application server version can be found at Console- Configuration- Infrastructure manager- Appserver details. And the RCP version is what you see when you launch the console. As per the recommendation, both should match.

The value in the registry is the max heap for the launcher. the launcher does not need 1024m of heap (though it would probably never actually claim that much). In the default setup, any new instances will inherit the maxheap setting from the launcher. you should really set the max heap explicitly on the instance, via infra mgr.